Machine-tool transmission and control mechanism



l1 Sheets-Sheet l J. B. ARMITAGE Filed June l1, 1937 MACHINE-TOOLTRANSMISSION AND CONTROL MECHANISM Aug. 15, 1939.

INVENTOR JOSEPH B. ARM'WAGE BY ATTORNEY Aug. l5, 1939. J. B. ARMITAGE2,159,484

MACHINE-TOOL TRANSMISSION AND CONTROL MECHANISK Filed June 11, 1957 -11snees-shet 2 INVENToR JosEPH B. ARMITAGE ATTORN EY Aug. 15, 1939. J. B.ARMITAGE MACHINE-TOOL TRANSMISSION AND CONTROL MECHANISM vFiled June ll,1957 ll Sheets-Sheet 3 INVENTOR BY JOSEPH B. ARMITAGE 77% imma? ATTORNEYAIg- 15, 1939. J. B. ARMITAGE v 2,169,484

MACHINE-TOOL TRANSMISSION AND CNTROL MECHANISM Filed June 1l, 1937 11Sheets-Sheet 4 r l 82 v INVENTOR JOSEPH B. ARMITAG:

ATTORNEY Aug. 15,1939. J. B. ARMITAGE MACHINE-TOOL TRANSMISSION ANDCONTROL MECHANISM Filed June l1, 1957 11 Sheets-Sheet 5 www ww ww mmvl||ll lNvENToR BY JQSEPH B. ARMITAGE ATTORNEY Aug. 15, 1939.

J. B. ARMITAGE MACHINE-TOOL TRANSMISSION AND CONTROL MECHANISH FiledJune l1, 1937 f' '1 I iuuuu las 11 Sheets-Sheet 6 Effie/Ja,

INVENTOR JOSEPH B. ARMITAGE BYW/ 176mm ATTORNEY Aug. l5, 1939. J. B.ARMlT-AGE 2,169,434

MACHINE-TOOL TRANSMISSION AND CONTROL MECHNISM Filed June ll, 1937 1lSheets-Sheet 7 KS .bs

VEN w kw INVENTOR J osEPH B. ARMITAGE BYW/ i'm? ATTORNEY Aug. l5, 1939.J. B. ARMITAGE MACHINE-TOOL TRANSMISSION AND CONTROL HECHANQISH FiledJune ll, 1937 ll Sheets-Sheet 8 ug. l5, 1939. B; ARMWAGE 2,169,484

MACHINE-TOOL TRANSMISSION AND CONTROL MECHNISM Filed June ll, 1937 11Sheets-Sheet 9 "rn a-r R x N v 5% Si B MQ @x INVENTOR JQSEPH B ARMITAGEATTORNEY Aug. 15, 1939o J. B. ARMITAGE 2,169,484

NmcHINE-ToolJ TRANSMISSION AND CONTROL MECHANISM Filed June ll, 1957 1lSheets-Sheet 10 Aug. i5, wis.

J. B. ARMITAGE MACHINE-TOOL TRANSMISSION AND CONTROL .MECHANISM 11snets-sheat 11 Filed June ll, 1937 mentes Aug. 1s, 1939 UNITED STATESMACHINE-TOOL TRANSMISSION AND CONTROL MECHANISM Joseph B. Armitage,yWauwatosa, Wis., assignor to Kearney & Trecker Corporation, West `Ailis,Wis., a corporation of Wisconsin Application June 11, 1937, Serial No.147,685

sv claims. (ci. sac-21) This invention relates generally to machinetools and more particularly to an improved power transmitting andcontrolling mechanism especially suitable for a milling machine.

A general object of the invention is to provide improved transmission'mechanism and control apparatus for actuating and controlling thevarious movable elements of a machine tool, such as a milling machine orthe like.

Another object of the invention is to provide improved transmissionmechanism and control apparatus especially suitable for actuating andcontrolling the movable elements of a milling machine of the rail orplaner type.

Another object is to provide an improved transmission mechanism fordelivering power to a tool spindle movably mounted on a milling machine.

Another object is to provide an improved driving mechanism for actuatinga tool spindle movably mounted on the rail of a rail type millingmachine.

Another object is to provide an improved trans- 1 mission mechanism fora milling machine of the movements of a plurality of elements of amachine tool at a common selected feed rate, and to provide forselectively moving any one of the elements at rapid traverse ratewithout disturbing the movement of any other element.

Another object is to provide an improved transmission mechanism formoving a heavy work table, the mechanism being controlled by a singlelever to effect movement of the table selectively in either direction atrapid traverse rate smoothly and without clashing of gears or positiveclutches.

Another object is to provide a transmission mechanism for a machine toolwork table, incuding a separate friction clutch for driving the table atrapid traverse rate in each direction.

Another object is to provide control means for a machine tool tabledriving transmission including a separate friction clutch for drivingthe table at rapid traverse rate in each direction and interlockingmeans to prevent engagement of a rapid traverse friction clutch when themeans for effecting feeding movement of the table in the oppositedirection is engaged.

Another object is to provide an improved man- 5 ually operated controlapparatus for the table driving transmission mechanism of a machinetool.

A further object is to provide an improved automatic trip mechanism forcontrolling the l0 table driving apparatus of a machine tool.

A still further object is to provide an improved machine tool tabledriving mechanism and control apparatus including power operatedautomatic reversing mechanism.

According to this invention, a large milling machine 'of the rail orplaner type, having a heavy work supporting table and a verticallymovable rail carrying a tool spindle, is provided with improvedcontrolling and driving mechanism for actuating the table and thespindle. 'I'he table controlling and driving mechanism includes a rapidtraverse rate driving apparatus having an individual friction clutch foractuating the table in each direction, the arrangement being such thatthe table may be moved selectively at rapid traverse rate in eitherdirection under the conl trol of a single lever without the necessity ofengaging positive clutches or sliding gears. Movement of the table atfeed rate is effected by means of a positive clutch driving anover-running clutch in such manner that transition from feed rate torapid traverse rate may be accomplished smoothly without stopping thetable or disengaging the positive clutch, the control levers beinginterlocked to prevent engagement of the friction clutch for movement atrapid traverse rate in one direction when the positive clutch foreffecting feeding movement in the opposite direction is engaged. Therate of feeding` movement i0 is regulated by a quick change gearshifting mechanism that is adjusted by means of a single control leverassociated With a dial indicating the rate of feed. Power for effectingfeeding movements of the vertical spindle in horizontal and verticaldirections is likewise derived from the feed rate gear changingmechanism. means being provided on the rail for determining the path oimovement andthe direction of movement of the spindle. An over-runningclutch is provided in the spindle feed drive to permit rapid traversemovement thereof upon engagement of a spindle rapid traverse frictionclutch, the feeding movement and rapid traverse movement of the spindlebeing independent ofmovement of the table. By

` on the rail is derived from a motor mounted ln the frame of themachine and is transmitted at relatively high Aspeed to a quick changegear shifting mechanism mounted on the rail and operative by a singlecontrol lever, a dial being provided to indicate the spindle speed. Arange 'changing mechanism is provided on the spindle supporting head foreffecting operation of the spindle in either of two speed ranges, thespindle speed being regulated by cooperative action of the rangechanging mechanism and the speed changing mechanism on the rail. Theadvantage of this arrangement is that at low spindle speeds, only' thespindle and associated mecha.- nism is subjected to high driving torque,the

transmission mechanism from the motor to the at its normal high speedand to transmit power at low torque, whereby minimum deflection ortwisting action is experienced in the transmission train.

The foregoing and other objects, which will becomemore fully apparentfrom the following detailed description of a machine tool exemplifylinga preferred embodiment of the invention, may vbe achieved by theparticular structure shown in and described in connection with theaccompanying drawings, of which:

Figure 1 is a view in right end elevation of a milling machine of therail or planer type, constituting an embodiment of the novel features ofthis invention;

Fig. 2 is a fragmentary view in front elevation of the part of themachine bed carrying the levers for controlling feeding movements of themachine parts;

Fig. 3 is a fragmentary frontal view, partly in section on the planerepresented by the lines 3 3 in,Fig. 13, showing the tripping arms andthe cooperating trip dogs on the front face 0f the machine table;

Fig. 4 is a fragmentary view showing parts of the power transmissiontrains, taken in transverse section through the machine frame in theregion indicated generally by the lines 4-4 in Fig. 2;

Fig. 5 is a developed, partially diagrammatic view of the spindle speedchanging transmission mechanism and spindle movement controllingmechanism in the gear box on the rail of the machine;

Fig. 6 is a view of the gear box, partly in front elevation and partlyin section on the plane represented by the line 6-6 in Fig. 7;

Fig. 6a is a fragmentary view of-the spindle speed control mechanism insection on the plane represented by the line (ia-6a in Fig. 6.

Fig. 7 is a view of the gear box in right side elevation with the coverremoved and with some parts in section on the plane represented by theline 1-1 in Fig. 6;

Fig. 8 is a detailed sectional view of part of the control mechanismtaken on the plane represented by the line 8-8 in Fig. 7,',

` Fig. 9 is a view of the spindle supporting unit in vertical section onthe plane represented by the line 8-9 in Fig. 1, showing the spindledrive mechanism and range changer;

Fig. 10 is a fragmentary view generally similar to Fig. 9 but on anotherplane, showing the spindle head elevating mechanism;

Fig. 11 is a fragmentary developed frontal view of the table moving feeddirection and rate changing mechanism in the bed of the machine,

shown partly in section taken longitudinally of the work table;

Fig. 12 is a fragmentary view ofthe clutchshifting mechanism for thetable moving transmission, partly yin section on the plane representedby the line i2-l2 in Fig. 2;

Fig. 3 is a viewl of the table controlling levers and automatic tripmechanism taken in transverse section on the plane represented by theline |3-I 3 in Fig. 2;

Fig. 14 is a frontal view of the control levers and interlockingmechanism, taken from the left in Fig. 13 and indicating variousoperating positions thereof;

Fig. 15 is `a frontal view of the control meehanism linkage, taken onthe plane represented b the line |5-I5 in Fig. 13;

Fig. 16 is a plan View of the tripping arms and associated mechanismpartly in section on the plane represented by the line lli-I6 in Fig.13;

Fig. 20 is a schematic diagram of the hydraulic control circuit for thereversing mechanism, the control `valve and other parts being shown inlongitudinal section generally similar to Fig. 18;

Fig. 21 is a view in longitudinal section of the control valve shown inFig. 20 but with the valve plunger in a different position; and

Fig. 22 is a view similar to Fig. 21 but with the valve plunger in stillanother position.

'I'he particular machine tool shown in the drawings as an example ofapparatus constituting a preferred embodiment of the invention, is amilling machine of the rail or planer type.

Referring particularly to Fig. 1, in which the machine is shown as awhole, it may be seen that the general structure includes essentially abase or bed 20 that carries a slidably mounted work supporting table 2|arranged for longitudinal reciprocatory feeding movement. Secured to thebed 20 at each side of the work table 2| are forward and, rear uprightsor side columns 22 and 23 respectively that are rigidly connected attheir tops by a cross head or tie rail cross member 24 in manner toconstitute with the bed 20 a rigid main frame structure for supportingthe operating mechanism of the machine.

The uprights 22 and 23 carry a cross rail 25 that is slidably mountedthereon for vertical adjustment, drive screws 26 and 21 being providedin the columns 22 and 23 respectively in engagement with the ends of therail for elevating or llowering it. A motor 28 is mounted on the crosshead 24 and is operatively connected to actuate the driving screws 28and 21 simultaneously in manner to move both ends of the railsynchronously, as more fully set forth in my Patent No.

2,081,288, issued May 25, 1937, and entitled Machine tool transmissionand control. After the rail 25 has been moved to adjusted position, itmay be clamped to the columns by actuating a clamping lever 23.

Slidably mounted on the rai 25 for horizontal movement relative theretoand for vertical movementbodily therewith, is a tool spindle supportingunit 39. The spindle supporting unit 30 includes a saddle 3| whichslidably engages the rail 25 and that carries a spindle supporting head32 arranged for vertical sliding movement relative to the saddle. Thespindle head 32 serves to rotatably support a vertically disposed toolcarrying spindle 33 in position to present a rotatable cutting tool incooperating relationship with a workpiece mounted on the reciprocatorywork table 2l, the arrangement being such that the cutting tool may bemoved vertically or transversely relative to the table. For transmittingpower to the spindle 33 to rotate it, there is provided atransmissiongear box 34 which is mounted on the forward end of the rail25 in manner to move vertically with the rail.

Slidably mounted on the columns 22 and 23 beneath the cross rail 25 arespindle supporting,

units 35 and 38 respectively, carrying horizontally disposed toolspindles 31 and 38. The spindle units 35 and 38 are arranged to beadjusted vertically along the columns by driving screws 39 and 40respectively, which may be operated manually by a hand crank applied tothe square ends of associated actuating shafts 4| and 42. The spindles31 and 38 are also arranged for longitudinal horizontal adjustment, foradjusting the position ofcutters carried thereby relative to a workpieceon the table 2 I, as more fully described in my previously mentionedpatent.

Power for rotating the tool supporting spindles 33, 31, and 38 isderived from a spindle driving motor 45, Fig. l, that is disposedlengthwise of the bed 28 adjacent to the rear upright 23. As shown inFig. 4, the shaft of the motor is connected to a worm 46, which engageswith and drives a worm wheel 41 on the end of a main driving shaft 48extending transversely of the machine frame Just to the right of theuprights. In the region of each upright, the shaft 48 is provided with abevel pinion, represented in Fig. by pinons 49 and 50respectively, whichmesh with bevel gears 5| and 52on the lower ends of vertically disposedsplined shafts 53 and 54, having sliding connections with the respectivespindle supporting units 35 and 38 for driving the horizontal spindles31 and 38 in manner more fully described in my previously mentionedpatent.

The main driving shaft 48 is extended forward at the front of themachine, and is provided with a bevel pinion 56 which engages a bevelgear 51 on the lower end of a vertically disposed splined ,throughsuccessive revolutions.

mentwith a reversing mechanism 8| that is associated lwith a quickchange speed adJusting mechanism A housed within the gear box 34 on theforward en'd of the rail 25, the gear box and associated mechanism beingvertically movable bodily with the rail. 'I'he reversing mechanismcomprises two bevel pinions 82 and 83 rotatably mounted concentric withthe vertical shaft 58. and both meshing with a pinion 84 on an inputshaft 85 constituting part ofthe speed changer A. Between the pinions 82and 83 is a slidably mounted reversing clutch sleeve 88 that is spllnedon and driven by the shaft 58'and that may be moved by a reversing lever81, shown in Fig. 1, to engage clutch teeth on its ends withcomplementary clutch teeth on the pinions 62 and 83 selectively. Byengaging one or the 'other of the pinions 62 and 83, the speed changerinput vshaft 85 may be caused to rotate in one or the other directionand consequently the spindle 33 may be driven thereby in eitherdirection, a neutral position being provided in which the clutch collar88 is disengaged from both of the reversing pinions for disconnectingthe drive train to the vertical spindle.

As shown in Fig. 5, the input shaft 85 of the speed changer A carries agear 10 which meshes with and drives a gear 1I on a primary shaft 12journaled in the gear box 34. The shaft 12 has slidably mounted thereontwo gear couplets' 13 and 14 respectively, which may be shifted to meshthe gears thereof with complementary gears of an idler gear cluster 15.A secondary shaft 18 disposed parallel with the shaft 12 is providedwith a slidably mounted couplet 11, the gears of which may be engagedselectively with complernentary gears of the idler cluster 'l5 in mannerto be driven thereby. The secondary shaft 18 is also provided with acouplet 18 that is slidably mounted to engage its gears with and drive ygears 13 and 80 respectively that are secured on a horizontally disposedsplined output shaft 3| which extends lengthwise of the rail 25 andfunctions to transmit power at a selected rate from the speed changer Ato the movable spindle supporting unit 30. A

As shown in Figs. 5, 6 and '7, the gear couplets 13 and 14 on theprimary shaft 12 are engaged by shifting forks 83 and 84 respectively,that'cooperate with and are shifted bya cam groove ,in a cam plate 85which is rotatably mounted fon` the inner surface of a side cover plate'82 Iofr the housing 34, as shown in Fig. 6a. Likewise, the couplets 11and 18 on the secondary shaft 16 are also engaged by shifting forks 81and 88 that cooperate respectively withv eccentrically disposed rollerscarried by control plates constituted by intermeshing gears 86 and 89that are rotattably mounted on the side cover plate 82 withinthe-housing 34 and adjacent to the cam plate 85, the gears 88 and 89being driven intermittently by a discontinuous gear on the cam plate.The plates 85, 86, and 89 are arranged to be rotated by means of a speedselecting lever or crank 90 mounted on the side cover plate 82 of thehousing enclosing the speed changer A, the operative connections beingso arranged that the sliding gear couplets are shifted to effect thevarious gear combinations successively to provide the several changes inspindle speeds of which the speed changer is capable, as the crank 99 isturned To avoid accidental locking of the mechanism, the groove of camplate 85 is so shaped as to prevent engagement of both the gear couplet13 'and the gear couplet 14 with gears of the idler cluster 15 at thesame time. In` order that all of the various gears might be showndistinctly, the shifting elements have been shown in neutral or out ofmesh position in Fig. 5. but it is to be understood that the shiftingmechanism does not provide for positioning the gears in the manner shownin this diagrammatic view.

Cooperating with the speed selecting lever 90 is a speed indicating dial9|, Fig. 1, provided with an outer row 92 and an inner row 93 bfindicia, the dial being operatively connected to the plates 85, 86, and89 in such manner that it is turned through one complete revolutionwhile the plates are moving through one gear shifting cycle.

From the speed changer A, power is transmitted through the splined shaft8| to the spindle unit 30. that is slidably mounted on the rail 25, theother end of the shaft 8| being journaled in the end of the railopposite from that occupied by the gear box 34. As shown in Fig. 9, theshaft 8| passes through the saddle 3| of the spindle unit, and hassplined connection with a bevel pinion 96 journaled in the saddle. Thepinion 9G meshes with a similar bevel pinion 91 on the lower end of averticallyl disposed splined'shaft98`that extends upward from the saddleinto a rearwardly projecting portion 99 of the spindle carrying head 32.die head is an internally and externally splined sleeve I| havingsliding connection with the splined shaft 98 in manner to be driventhereby and to permit relative longitudinal movement therebetween whenthe spindle head 32 i is moved vertically relative to the saddle 3|.Slidably mounted upon the splined sleeve I 0I is a,

range changing gear couplet |02, the gears of which` are disposed to beengaged selectively .with

va relatively small gear |03 and a relatively large gear |04 secured onthe upper end of the tool supporting spindle 33, the cooperating gearsconstituting a range changer B for driving the spindie 33 in either oneof two speed ranges.

The range change couplet |02 may be shifted by means of a range changinglever |05, shown in Fig. 1, which may be moved from the position shownin full lines to the position shown in dotted lines to move the couplet|02 from the low speed range position to the high speed range position.

The particular gear shifting mechanism shown in Fig. 5 as constitutingthe speed changer A is capable of effecting sixteen different speeds ofoperation of the splined shaft 8|, and since either of two ranges may beeffected by adjusting the range changer B, the spindle 33 may be drivenat any one of thirty-two speeds by appropriate settings of the speedchanger A and the range changer lB cooperatively. As previouslyexplained in connection with Fig. 1, the speed indicating dial 9| of thespeed changer A is provided with two circular rows of indicia, one rowof indicia being used to indicate the speed when operating in one speedrange and the other row being used when operating in the other speedrange. As shown in Fig. 1, a stationary indicator |06 is disposed tocooperate with the outer row 92 of in- A diciafand a stationaryvindicator |01 is positioned to cooperate with the inner row 93, theindicators |06 and |01 being marked respectively S and F to correspondwith the slow and fast positions of the range changing lever |05whereby.. the machine operator may determine the spindle speed by notingthe indicia adjacent to the indicator Correspo'nding with the speedrange established byA therange changing lever |05.`

Journaled within the portion 99 of the spin- This arrangement of speedchanging gearing is found to be especially advantageous when the spindle33 is operated at low speed, for under these conditions the drivingtorque of the spindle is ordinarily high and since the range changer Beffects considerable speed reduction in the low range position, only thespindle and the gear |04 attached thereto are subjected to the highdriving torque. By reason of the speed reduction in the range changer,both the vertical splined shaft 98 and the horizontal splined shaft 8|in the spindle unit 30 operate at speeds considerably higher than thespindle speed. Since bothV the speed changer A and the range changer Bare carried by the rail 25, the transmission train from the spindledriving motor 45 to the speed changer A, including the main shaft 48extending behigh speed and to transmit relatively low torque,

with the beneficial result that there is little deflection or twistingof the shafts in the driving train and consequently a smooth and steadydriving torque is applied to the spindle, providing a powerful drivingeffect without vibration or chatter.

Power for moving the work supporting table 2| longitudinally of the bedand for moving the spindle carrying head 32 vertically and horizontallyupon the rail 25, is derived from a feed driving motor I I5 mounted onthe front side of the forward upright 22, as shown in Fig. 1. The shaftof the motor I I5 is connected to a worm I I6 which meshes with a wormwheel I I1 as shown in Fig. 11, the worm wheel ||1 being secured to adriving shaft |I8 extending longitudinally of the bed 20 beneath thetable 2|. As shown in Fig. 11, the feed driving shaft 8 -extends to theright and is connected at its right ed to transmit power to a feed rategear changing mechanism C a pinion IIS being provided on the end of theshaft I I8 in meshing engagement with a gear wheel |20 on a primaryshaft I2I of the rate changer.

Slidably mounted on the primary shaft I2| are two gear couplets |22 and|23 respectively, which may be moved to mesh their gears withcooperating gears of an idler gear cluster |24. A secondary shaft |25carries a slidably mounted gear couplet |26 adapted to be meshedselectively with and to be driven by gears of the idler cluster |24. Theshaft |25 also carries fixed gears |21 and |28 with which the gears of acouplet |29 may mesh, the couplet |29 being mounted on a safety clutch|30 which is slidably splined on a tertiary shaft I3I. The tertiaryshaft I3I is provided on its left end with a small pinion |32 havingmeshing engagement with a gear |33 on the right end of a. feed ratedriving shaft |34, which is driven thereby at the speed established bythe feed rate changer C.

'Ihe mechanism (not shown) for shifting the various sliding couplets ofthe rate changer C may be generally similar to the cam actuated shiftingapparatus of the speed changing mechanism A mounted on the rail 25, arate selecting lever |40 and a feed rate indicating dial I4I on thefront of the machine l(Fig. 2) being associated with the shiftingmechanism for establishing the desired rate of feeding movement of thetable or spindle, the arrangement being such that both the table 2| andthe spindle carryinghead 32 operate at the same feed rate.

'Ihe mechanism for moving the table 2| longitudinally of the bed 23includes a non-rotatable table screw |45 thatais xed at its ends to theends of the table and that cooperates with a rotatable table driving nut|46 journaled in the bed in manner capable of exerting longitudinaldriving force on the screw |43. For rotating the nut |43 in direction todrive the table to the left, there is provided a gear train including agear |41 fixed to the nut and meshing with a gear |43 rotatably mountedconcentric with the feed driving shaft |34. For driving the table in theother direction-that is. to the right-a gear train is provided includinga gear |43 xed on the nut |43 and meshed with a reversing idler pinion|33 which in turn is meshed with a gear i'i also rotatably mountedconcentric with the feed driving shaft |34.

For effecting a. driving connection from the feed driving shaft |34 tothe table driving gear |43 or to the table driving gear ibi, there isprovided on the shaft |33 between the gears a slidably keyed positiveclutch sleeve |53 having at its ends positive jaw clutch teeth |54 and|53 respectively. f

The clutch teeth |54 of the clutch sleeve are disposed to be meshed withcooperating clutch teeth |36 on the end of a sleeve |31 which isrotatably mounted on the shaft |34 and that rotatably supports the drivegear |43. `The sleeve |51 is connected by means of an over-runningclutch |58 to the gear |48 in manner to drive it and its meshing gear|41 constituting the train for driving the table 2| in direction fromright to left. In order to drive the table 2| in the reversedirection-that is, from left to right-the clutch sleeve |53 is shiftedto the right to engage the teeth |35 at its other end with cooperatingclutch teeth |63 on the end of a sleeve ii rotatably mounted on'theshaft |34 and rotatably supporting the gear |5| to which it is connectedby means of an overrunning clutch |32, the gear |5| acting through thereversing idler |53 and the gear |43 to turn the table driving nut |46in the reverse direction.

For driving the table 2i in either direction at rapid traverse rate, twofriction clutches are provided for selectively connecting one or theother of the table driving trains respectively directly to the supportdriving shaft H3 which operates at relatively high speed. As shown inFig. il, a friction clutch |63 is provided on the shaft H3 and arrangedin manner to selectively couple a gear |33 thereto. A similar frictionclutch |33 is arranged to selectively couple a gear |31 to the shaft, ashifting collar |33 being slidably mounted on the shaft between theclutches and operable to engage` either the one or the other clutch. Thegears |33 and |31 are meshed respectively with gears |63 and |13 whichare fixed with the table driving gears |43 and |5| respectively, theoverrunning clutches |53 and i62 being operative to permit transitionfrom feed rate to rapid traverse rate upon engagement of one or theother friction clutch without first disengaging the feed rate drivingpositive clutch |53.

Power for moving the spindle carrying head 32 relative to the table 2|at the feed rate deteru end of a shaft |18. The shaft |13 is providedwith a bevel pinion |19 that meshes with a bevel pinion |33 on the endof a forwardly extending shaft |8I. As shown in Fig. 4, the shaft |3| isprovided on its forward end with a bevel pinion |82 meshing with a bevelpinion |33 on a vertically disposed stub shaft |34. The shaft |34 isvprovided with a gear |85 meshing with a similar gear |36 on the lowerend of a vertically disposed spllned shaft |31 extending upward from thebase of the column 22 parallel with the spindle driving shaft 38,enclosing tubing |33 being provided to protect the shaft from foreignmaterial and from injury.

As shown in Fig. 1, the shaft |31 extends upwardly into the gear box 34on the forward end of the rail 23 in which it has splined connectionwith a bevel pinion |3i, that is shown in Fig. 5, journaled in the box.The pinion |3| meshes with a similar bevel pinion |32 which is fixedwith a spur gear |93 that drives a similar spur gear |94 on a-shaft |33also journaled in the gear box 34. The shaft |35 is provided with a gear|93 that meshes with a clutch gear |31 rotatably mounted on acylindrical end portion of a threaded screw shaft |33, the threadedportion of which extends from the gear box longitudinally of the railand is journaled at its other end in the op,- posite end of the rail, asshown in Fig. 1. A second gear |93 mounted on the shaft |35 meshes witha reversing pinion 233 which engages a second clutch gear 23| alsorotatably mounted on the shaft |98 and disposed in opposition to theclutch gear |91, the gear 23| being rotated in direction opposite tothat of the gear |91. Between the clutch gears |31 and 23|, there isprovided a shiftable clutch spool 232 which is slidably keyed to thethreaded shaft |93, and which may be moved from the neutral positionshown to couple either of the clutch gears t'o the shaft |98 to drive itin either direction selectively. As may be seen in Figs. 9 and l0, thethreaded shaft |33 has threaded engagement with the saddle 3| of thespindle unit 33, the arrangement being such that the saddle may be,moved lengthwise of the rail in either direction upon turning thethreaded .dinal movement of the saddle 3| along the rail 25, the controlrod 235 is provided with stop collars 233 disposed to be engaged by thesaddle and to effect longitudinal movement of the rod 235. As shown inFig. ,'1, the rod 235 enters the gear box 34 and is provided thereinwith spaced collars 231 that engage one arm of a bell crank 233. Theother arm of the bell crank 238 is geared to an arm of a similar bellcrank 233 which engages with its other arm a shifting sleeve 2|3carrying a shifting fork 2li that engages the clutch spool 232, thearrangement being such that when the rod 235 is moved longitudinally bythe saddle 3|. engaging a stop collar 233, the linkage effects movementof the clutch spool 232 to neutral position, thereby disengaging theshaft |93 from the driving clutch gear.

For engaging the clutch spool 232 with one of the clutch gears to movethe saddle in selected direction, there is provided on the side of thegear box 34 an actuating lever 2|5 connected to turn a shaft 2|6, asshown in Fig. l, the shaft 2|3 being provided with a slotted collar 2|1,Figs. '7 and 8, that cooperates with a pin 2|3 on an arm of the shiftingsleeve 2i3 in manner to effect shifting movement of the shifting fork2|| when the lever 2| 5 is actuated. As shown in Fig. 7, the collar 2|1is provided with detentnotches 220 that cooperate with a spring-presseddetent 22| for positioning the clutch spool shifting mechanism inneutral position or in either of its positions for moving the saddle 3|in either direction along the rail. To insure that the saddle will notbe moved by power unintentionally, the directional control lever 2 I 5is provided with a locking pin 222 for locking the lever in neutralposition.

For moving the spindle unit 30 along the rail manually, the forward endof the screw shaft |98 is provided with a bevel pinion 225 (Fig. 5)within the gear box 34 which meshes with a similar bevel pinion on ashaft 226, extending through the cover of the gear box and presenting asplined end for receiving an operating crank, not shown. As shown inFig. 1, the splined end of the shaft 226 is disposed adjacent to thecontrol lever 2I5 in such position that an interference ring 221 on thelever 2|5 prevents engagement of the hand crank when the power drivingmechanism is engaged. Likewise, the interference ring 221 preventsmovement of the lever 2|5 when the hand crank is engaged with the shaft226, thus making it impossible to engage the power feed with the handcrank attached, which would otherwise result in spinning of the crankwith danger of injury to the operator.

The mechanism for moving the spindle carrying head 32 verticallyrelative to the saddle 3| includes a splined spindle elevating shaft230(Figs. 1 and 5) disposed longitudinally of the rail 25, parallel withthe threaded shaft |98, and having rotatably mounted on its forward endwithin the gear box 34 a pair of opposing clutch gears 23| and 232 whichmesh respectively with the clutch gears |91 and 20|, which are driven inopposite directions, as previously explained. Between the clutch gears23| and 232 is a clutch spool 233 that is slidably keyed to the shaft230 in manner to be moved to couple either of the gears to the shaft fordriving it in either direction selectively. As shown in Fig. 10, theshaft 230 passes through the saddle 3| and has splined connectiontherein with a bevel pinion 235 which is journaled in the saddle andwhich has meshing engagement with a bevel pinion 236 on the lower end ofan elevating screw shaft 231 extending upward from the saddle. 'Iheupper portion of the shaft 231 has threaded engagement with aninternally threaded sleeve 238 that depends from the rearwardlyprojecting portion 99 of the spindle carrying head 32, the arrangementbeing such that when the shaft 231 is rotated the head 32 is movedvertically relative to the saddle 3|.

For limiting the vertical movement of the head 32 by power, trippingmechanism is provided as shown in Fig. 1, including trip dogs 239adjustably mounted on the head and cooperating with a tripping arm 239'on the saddle 3|, the arm being connected to turn the trip rod 205 whenthe head arrives at predetermined position. As shown in Fig. 6, the triprod 205 is provided within the gear box 34 with a gear segment 240engaging rack teeth on a vertically movable trip rod 24| having a slotand pin connection with one arm of a bell crank lever 242. The other armof the bell crank 242 carriesa shifting yoke 243 that engages the clutchspool 233, the arrangement being such that when the trip rod 205 isturned by the trip mechanism, the connecting linkage moves the clutchspool 233 to neutral position,

thereby disconnecting the power drive from the spindle elevating shaft230.

For engaging the clutch spool 233 to effect power 'movement of thespindle head 32in selected direction, there is provided a directionselecting lever 245shown in Fig. 1, mounted on the side of the gear box34, and carried on the outer end of a shaft 246 which is provided on itsinner end (Fig. 7) with an arm 241 having a slot and pin engagement withthe end of an arm 248 that is connected to turn the clutch shifting bellcrank 242. The arm 241 is provided with detent notches 246 thatcooperate with a spring pressed detent 250 to retain the lever I245 andthe clutch spool 233 either in the neutral position or in one or theother operating position. To prevent movement of the spindle head 32vertically by power unintentionally, the lever 245 is provided with alocking pin 252 by means of which it may be locked in neutral position.

For moving the spindle head 32 vertically by hand, there is provided onthe front of the gear box 34 a handwheel 255 by means of which a shaft256 may be turned, the shaft having gear teeth at its inner endconstituting a pinion 251 which meshes with a gear 256 on the forwardend,

of the spindle elevating shaft 230. To prevent the handwheel 255 frombeing rotated by power i when the elevating clutch spool 233 is engagedwith a power driving clutch gear, the handwheel is operatively connectedto the shaft 256 by means of a lpositive clutch 260 that may be moved todisengaged position by a rod 26| extending longitudinally through theshaft 256. At its inner end the rod 26| is engaged by theend of a lever262 pivotally mounted in the gear box and provided with a detent arm263, Fig. 7, that cooperates with a cam plate 264 carried by thevertically disposed control rod 24|, the arrangement being such thatwhen the clutch spool 233 is in neutral position, the detent Aarm 263engages a notch in the cam plate 264 and permits the clutch 260 to beengaged for coupling the handwheel 255 to the shaft When the clutchsleeve 233 is moved in either direction into engagement with a drivinggear, the cam plate 264 is moved to force the detent 263 out of thenotch against the resistance of a spring 265, thereby turning the arm262 and moving the rod 26| to the left as seen in Fig, 5, to disengagethe clutch 260, the spring functioning to re-engage the clutch 260 whenthe clutch sleeve 233 is returned to neutral position. The spindle head32 may be locked in vertical position relative to the saddle 3| by meansof mechanism including a clamping lever 266.

For effecting movement of the spindle 33 at rapid traverse rate alongthe path and in the direction established by the directional controllevers 2 I5 and 245, there is provided a rapid trav- .erse frictionclutch 210, mounted directly on the feed motor driven shaft ||6, Yasshown in Fig. 11, and operative to selectively couple a gear 21| to theshaft I|8. The gear 21| meshes with a gear 212 mounted on theover-running clutch |15, the arrangement being such that when thefriction clutch 210 is engaged, the gear 212 and the gear |16 on theover-running clutch |15 are rotated at rapid traverse rate, with theclutch |15 overrunning the feed driving shaft |34.

For actuating the friction clutch 210, there is provided a clutchshifting sleeve 213 which is slidably mounted on the shaft I I8 and thatmay be moved to engage or disengage the clutch by means of a shiftingfork 214 actuated by a. spindle rapid traverse lever 215, as shown inFig. 4,

the lever being mounted on the front of the machine in positionaccessible to the operator, as shown in Fig. 2. The rapid traverse lever215 is carried on -the end of a shaft 216 journaled in the bed 281 andprovided at its inner end with an arm 211 which engages the shiftingfork 214 for moving it and the clutch sleeve 213 longitudinally of theshaft ||8. By reason of the independent rapid traverse friction' clutch218, the spindle carrying head 32 may be moved at either feed rate orrapid traverse rate along the path and in the direction determined bythe control levers 2|5 and 245 independently of the work table 2| andregardless of whether the table is stationary or is moving in eitherdirection at either feed rate or rapid traverse rate. Likewise, thetable 2|may be operated at either feed rate or rapid traverse rate ineither direction-by suitably shifting the clutch sleeve |53 and theshifting collar |68, independently of movement of the spindle head 32.However, the feed rate at which either the spindle head 32 or the table2| maybe moved is determined by the feed rate changing mechanism C whichestablishes a common feeding rate for both movable elements, the ratebeing indicated by the dial I4| on the front of the bed 28.

For controlling movement of the table 2| at feed rate, there is providedon the front of the machine a feed control lever 288 that is connectedto turn a control shaft 28| extending transversely through the bed andprovided at the rear of the machine with a rear feed control lever 282,as shown in Fig. 13. The feed lever 288 has pivotally connected to itone end of a control link 283 which connects it with an armI 284 on aclutch shifting shaft 285 as shown in Fig. 2. As shown in Fig. 12, theshifting shaft 285 is provided at its inner end with a shifting yoke 286that engages the clutch sleeve |53 o'n the feed rate shaft |34, theconnections being such that by moving the lever 288 from side to side,the clutch sleeve |53 may be moved into engagement with the clutch gear|48 or the clutch gear |5| to eiect movement of the table in eitherdirection at feed rate, the table moving in the direction in which thelever is moved.

For controlling the movement of the table at rapid traverse rate, thereis provided in front of the feed lever 288 a rapid traverse controllever 298 connected to turn a control shaft 23| disposed just 'below andparallel with the control shaft 28 The shaft 29| also extendstransversely through the bed and is provided at its other end with arear control lever 292. The control lever 288 is pivotaliy connected toone end of a link.283

which engages at its other end an arm 288 on a shifting shaft i285disposed adacent to and parallel with the shifting shaft 285. As shownin Fig. 12, the shifting shaft285 is provided at its inner end with ashifting yoke 286 which engages the rapid traverse clutch shiftingcollar` |38 on the shaft H8. By movement of the lever 238 from side toside, the shifting collar |63 is moved to engage either the frictionclutch |84 or the friction clutch it to effect movement of the table 2|,in the direction of movement of the lever, at rapid traverse rate, theover-running clutches |58 and |82 in the feed drive mechanism permittingtransition from feed rate to rapid traverse rate in the same directionwithout disengaging the feed rate positive clutch spool |53.

To prevent accidental engagement of a rapid traverse friction clutchwhile the positive clutch for effecting feed rate :movement in theopposite direction is engaged, the feed rate control lever 238 hasassociated with it a segmental interlocking member 388. As shown inFigs. 13 and 14, the interlocking segment 388 is connected to thecontrol shaft 28| to turn with it andthe lever 288, and it is providedat its ends with interference pins 38| and 382 respectively. Referringto Fig. 14, when the feed lever 288 is moved from the neutral position Nto feed position F, indicated by the dotted circle, to effect feedingmovement of the table 2| to the right, the segment 388 is likewise movedto the right to the dotted line position also indicated by the letter F.In this position, the interference pin 38| is brought near to theneutral position of the levers, and should the rapid traverse controllever 298 be moved to the left to engage the friction clutch |84 formoving the table to the left at rapid traverse rate, the lever 238 wouldfirst engage the pin 88|. Further movement of the lever would then turnthe segment 388 to the left, thereby turning the control shaft 28| anddisengaging the positive clutch for effecting feeding movement of thetable to the right. By thisarrangement, the positive clutch isdisengaged before the friction clutch. is engaged, thereby preventingdamage to the mechanism which might otherwise result should the rapidtraverse clutch for movement in one direction be engaged while the feedclutch for movement in the other direction is engaged.

As more fully set forth in my previously mentioned Patent No. 2,081,288,the electrical controls for the spindle driving motor v415 and the feeddriving motor |15 are so interlocked that the feed motor doesnotnormally operate unless the spindle driving motor is operating, to avoidthe possibility of feeding a workpiece against a stationary cutter.However, as it is desirable to provide for movement of the table 2| orthe spindle head 32 at rapid traverse rate while the spindle drivingmotor 45 is not operating, as when setting up a workpiece, there isprovided an auxiliaryI switch 385 indicated in Fig. 2, which isconnected by means of a link 386 to be operated bythe rapid traverselever 298, the arrangement being such that when the lever 288 is movedto rapid traverse position in either direction, the switch 385 is closedto energize the feed driving motor H8 .independently of the spindledriving motor. A control panel 381 on the front of the machine presentspush buttons for starting and stopping the various motors.

To provide for automatically controlling movement of the work table 2 i,the forward face of the table is provided with two T slots 3|| and 3|2,as shown in Figs. 3 and 13, for receiving trip dogs, the upper slotcarrying dogs for functioning when the table is moving from left toright and the lower slot, carrying dogs which are effective duringmovement of the table from right to left.` For stopping the tableautomatically, there is provided a trip arm 3|8 carried on the inner endofA a sleeve or hollow shaft 3| 4 that is journaled horizontally in theupper edge of the bed 28 adjacent to the forward face of the table.

' As shown in Fig. 13, the trip arm M3 is adapted sleeve 3|4 to thecontrol shaft 28| is so arranged that when the trip arm 3|3 ls inhorizontal position, the feed lever 288 is `in vertical or neutralposition indicated by the letter N, and when the feed lever 288 is movedto the right to position F 10 for effecting feeding movement of thetable to the right, the arm 3|3 is moved upward to position F, showndotted in Fig. 17, into the path of movement of the stop dog 3|5. At apredetermined position of the table in its course of movement, the stopdog 3|5 engages the arm 3|3 in manner to move it back to position N,thereby disengaging the feed driving clutch. sleeve |53 and stopping thetable. For retaining the feed lever 288 and the trip arm 3|3 in neutralposition or in either feeding position, the arm 328 on the control shaft28| is provided with detent notches 322 which are engaged by a springpressed detent 323, as shown in Fig. 15.

To provide for starting the table in the same direction after it hasbeen stopped by a stop dog, the sleeve 3|4 is slidably mounted in mannerto permit withdrawing the tripping arm 3|3 from engagement with the stopdog, a helical spring 325 being positioned as shown in Fig. 13,

30 to normally hold the sleeve in its forward or ac- ,tive position. Foreffecting movement of the sleeve 3|4, the feed lever 288 is pivotallymounted on a pin 326 which connects it to the control shaft 28|, inmanner to permit movement of the lever 288 toward or from the machine inthe plane of the shaft 28|. When the lever is moved forward away fromthe machine, the. lower end thereof engages a sliding key 321 fitted inthe shaft 28|, as shown in Fig. 15, and that engages at its inner Vendwith the lower end of a lever 328 that is pivoted near its mid-portionon the bed 28 and that engages with its upper end a shoulder formed bythe arm 3|8 on the sleeve 3|4, as shown in Figs. 13 and 16, theoperation being such that forward movement of the lever 288 moves thesleeve 3|4 forward against the resistance of the spring 325 andwithdraws the trip arm 3|3 from engagement with the stop dog. The lever288 may then be moved to re-engage the feed clutch, the arm 3|3 'passingin front of the trip dog.

A second trip-arm 338 disposed adjacent to the trip arm 3|3 is providedfor automatically changing the rate of movement of the table from feedrate to rapid traverse rate or vice versa. As

shown in Fig. 13, the arm 338 is carried on a shaft 33| journaled in andextending through the hollow sleeve 3| 4. At its forward end, the shaft33| is provided with an arm 332 pivotally connected to the upper end ofa vertical link 333'that is pivotally connected at its lower'end to anarm 334 on the rapid traverse clutch control shaft 29|, the arrangementbeing such that when the rapid traverse control lever 298 is in verticalor 85 neutral position N, the trip arm 338 is in horizontal position,likewise designated N and shown in full lines in Fig. 17. When the rapidtraverse lever 298 is moved to rapid traverse position R, indicated bythe dotted circle in Fig. 14, the rapid ,traverse trip arm 338 is movedto its uppermost position R, shown in dot-dash lines in Fig, 17.

To, change the rate of table movement from rapid traverse rate to feedrate, a ieed rate dog 335 may be provided in the T slot 3|| to engagethe arm 338 and force it downward from vits raised position R, therebyturning the control yshaft 29| upon the trip arm when the table ismoving fromright to left.

In order that the proper rapid traverse dog may act upon the rapidtraverse trip arm 338, means arme provided for turning the arm to moveit out of the path of action of one dog and into the path of action ofthe other dog. For this purpose, the interlocking segment 388 associatedwith the feed lever 280 is provided with a slot 348 that receives a pin34| on the rapid traverse lever 298, as shown in Figs. 13 and 14. Whenthe feed lever 288 is moved to actuate the table at feed rate, forexample: to the position F indicated in Fig. 14, the end of the slot 348in the segment 388 engages the pin 34| on the rapid traverse lever 288and moves it a short distance to the dotted circle position F, therebeing suicient lost motion in the linkage to permit this movementwithout engaging the rapid traverse clutch. With the rapid traverselever 298 in position F, the rapid traverse trip arm 338 is turned toposition F as shown in Figs. 3 and 17.

As shown in Fig. 3, the upper lug 336 of the arm 338 is thereby movedinto position to be engaged and lifted bythe upper rapid traverse dog338 as the table moves ,from left to right, and at the 336 out of thepath of movement of the dog'A 338. t When it is desired to operate thetable at rapid traverse rate without rst engaging the feed rate drive,the pin 34| of the lever 298 may be dis- '7 engaged from the slot 348 inthe interlocking seg- 1.

ment 388 by pivoting the lever 298 forward about shaft, 29|, a spring344 being provided to normally retain the lever in its inner positionwith, However'' the pin in engagement with the slot. the forwardmovement of the lever 298 is so limited in extent that the lever cannotbe moved past the pins 38| and 382 at the ends of the interlockingsegment 388, the pins serving at all times to prevent engagement of arapid traverse clutch while the feed clutch for movement in the oppositedirection is engaged.

By reason of the fact that the feeding movement of table 2| is 'effectedby a clutch of the positive jaw type, it is possible to stop the tableby means of a stop dog at an accurately predetermined position, sincethe clutch teeth disengage instantaneously and completely upon movementof the tripping arm 3|3 to a predetermined position. Likewise, it isespeciallyr advantageous to utilize control' mechanism employing the twofriction clutches |64 and |65 for effecting rapid traverse movement ofthe table, since either clutch may be engaged by the ra l)id a pivot pin343 which connects it to the control v traverse lever 288 to move thetable. selectively at rapid traverse rate in either direction withoutthe necessity of 'shifting gears or positive clutches to effect reversaland without shock or excessive strains upon the. transmission mechanism,the clutches being engaged smoothly to quickly effect movement in eitherdirection by simply moving the lever 288 to the rght or to the left, asmay be desired.

From the foregoing description of the automatic tripping mechanism, itis apparent that the rate of movement ofthe table 2| may be changed orthe table stopped by means actuated directly Aby the moving table..Inasmuch as no further movement of the shifting mechanism can beeffected directly by -the table after the clutches are disengagedrandthe table stops, it is necessary, in order to effect automatic reversalof the direction of table movement, to provide auxiliary power means formoving the clutches through the neutral position to a position causingtable movement in the opposite direction. For this purpose, the machinemay be equipped with an auxiliary power reversing mechanism of the typeshown in Figs. 18 to 22, utilizing fluid pressure for shifting theclutches.

Referring particularly to Figs. 18 and 19, the power shifting mechanismthere shown is adapted to be mounted on the front of the machine bed 28,in the region of the control levers. The apparatus comprises essentiallya hydraulic cylinder 358 provided with a cooperating piston 35|connected to effect movement of the positive clutch sleeve |53 forcontrollng feeding lmovement of the table, and another similar cylinder352 provided with a cooperating piston 353 that is arranged to actuatethe rapid traverse clutch controlling collar |68, a control valve 354being providedfor controllingthe admission of fluid pressure to thecylinders.

As shown in Fig. 18, the feed controlling piston 35| in the cylinder 358is carried on a piston rod 356, the end of which is provided with a yoke351 that engages a sliding block 358 carried by the shifting link 383,the arrangement being such that movement of the piston within thecylinder shifts the link 283 to move the clutch sleeve |53 in the samemanner that shifting of the clutch sleeve is effected by the feeddirection control lever 288. The piston 353 in the cylinder 352 islikewise carried on a piston rod 358 provided with a yoke 368 whichengages a sliding block 36| on the` shifting link 283 in manner toactuate the rapid traverse clutch shifting collar |68 in the way inwhich it is actuated by the rapid traverse control lever 288.

Shifting of the control valve 354 to effect power shifting of the feedand rapid traverse clutches is accomplished by means of reversing triprods 365 and 366 respectively, which are positiored to\ be engaged byreversing trip dogs such as the dog 361 shown mounted in the lower Tslot 3|2 of the table 2| in Fig. 19. As shown in Fig. 18, the trip rods365 and366 act upon the respective ends of a pivotally mounted lever368, the arrangement being such that the lever is rocked in onedirection or the other upon down- 'ward movement of the respective triprods. The

pivoted lever 368 is provided with a depending arm 369 which engages across head 318 connected with a plunger 31| of the valve 365 for movingthe plunger longitudinally within a cooperating valve casing 312. j

Referring to the'control circuit diagram shown in Fig. 20, uid pressurefor operating the hystance: the trip rod 366, is depressed by acothrough a conduit 393 communicating with a of the cylinder 352 escapesthrough a conduit v v l9 draulic `reversing mechanism is 'derived from apressure pump 315 which may be the pump for providing lubricating oilunder pressure to the moving parts of the machine, and which is drivenby means of a. downward extension of the ver- 5 tically disposed splinedshaft 58, as shown in Fig.

4. With the valve plunger 31| in the central or neutral position, asshown in Fig. 20, oil under pressure from the pump 315 flows through aconduit 316 to a valve port 311 in the valve casing 312 and vthencethrough a conduit 318 to a. valve port 318, which is in communicationthrough :i groove 388 in the valve plunger with a port 38| communicatingwith a low pressure relief valve From the relief valve 382, the oilflows through a conduit 383 to the lubricating system of the machine orto any other outlet providing escape at low pressure.

When one of the reversing vtrip rods, for inoperating reversing dog, thevalve plunger 31| is 20 moved to the left to the position shown in Fig.2l. With the valve in this position, the valve port 38| leading to thelow pressure relief valve 382 is closed, thus forcing the oil underpressure to escape from the port 3,18 through a conduit 384 to a highpressure relief valve 385 which permits escape of the oil only after apredetermined high pressure has been established in the system. As soonas vthe valve plunger 31| has been moved to the left by the reversingdog a sufficient distance to register a groove 386 therein with thepressure port 311 in the casing 312, the oil under pressure flowslongitudinally of the valve plunger through a conduit 381 therein, to acylinder 388 formed'in the right end of the casing, exerting pressure`therein on the end of the valve plunger to force it quickly to itsextreme left position.

Fluid pressure from the port 311 then passes through a groove 398 in thevalve plunger to a port 39| in the casing which communicates by 45 theright, thereby actuating the shifting mechanism in manner to engage theclutch sleeve |53 for driving the table at feed rate to the right. Fluidin the right end of the cylinder 358 escapes valve port 394 thatconnects through a groove 50 395 in the plunger with a port 386 which isopen to the atmosphere.

When the piston 35| arrives at the right end of the cylinder 358, ituncovers a port 388 at the micldlev of the cylinder through which thefluid enters a conduit 399 leading to a rate selecting valve 488, thefluid passing through a groove 48| of the valve into a conduit 482leading to a port 483 in the valve casing 312. The port 483 communicatesthrough a groove 484 in Ithe valve plunger with av port 485 connected byal conduit 486 to the right end of the cylinder 352. Pressure in theright end of the cylinder 352 forces the piston 353 therein to the left,turning the shifting shaft 295 clockwise and causing the clutch shiftingcollar |68 to engage the rapid traverse clutch for moving the table atrapid traverse rate to the right. Fluid in the left end .m

481 to a valve port 488 that communicates through a groove 489 in thevalve plungerl to a port 4|8 that is open to the atmosphere.

When the piston 353 arrives at the left end rof 75

